Source Fault Analyses from InSAR Data and Aftershocks for the Fin Doublet Earthquakes on 14 November 2021 in Hormozgan Province, South Iran

Document Type : Research Article

Authors

1 Corresponding Author, Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran. E-mail: rezapour@ut.ac.ir

2 Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran. E-mail: m.jamalreyhani@ut.ac.ir

Abstract

The Fin doublet earthquakes with magnitudes MN 6.2 and 6.3 occurred on November 14, 2021 in Hormozgan province, south of Iran, and were followed by many aftershocks with magnitude range between MN 2.5 and MN 5.0. In this study, first we conducted the InSAR analysis using the satellite data from European Space Agency (ESA) to the Fin doublet earthquakes. The displacement field obtained from interferometric observations in ascending and descending directions, exhibit ~E-W oriented pattern reverse fault. Then, we relocated aftershocks that were recorded between November 14, 2021 and January 14, 2022, using the double-difference relocation method (hypoDD). The general pattern of relocated aftershocks distribution shows a seismic zone covering an area of approximately 25×17 km2. The cross-sections through aftershock locations show that the dominant depth range of aftershocks is from ~4 to ~23 km. The results show that the focal depths decrease toward the northeastern part of the region and deeper-aftershocks are located in the southwestern part. The interferometric observations and distribution of relocated aftershocks suggest the source fault(s) of the Fin doublet earthquakes strikes along a nearly west–east line and dip toward south-to-southeast.

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References

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Journal of the Earth and Space Physics
Volume 48, Issue 4
online publication date: 5 March 2023
March 2023
Pages 87-97

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